Chia (Salvia hispanica L.) is a member of the Lamiaceae or mint family. The chia plant is a dicotyledonous annual that reaches about 1.75 m in height. The plants have opposed leaves that are 4-8 cm long and 3-5 cm wide. The flowers are purple, blue, or white and the inflorescence is a pedicellate having six or more flowers on the rachis. Chia seeds are small ovals with a diameter of about 1 mm. The seed color can be black, brown, mottled, or white. Chia is grown commercially for its seeds that are rich in omega-3 polyunsaturated fatty acids (58-64% of total lipids; 31-35% lipids by mass of the seed). Chia and chia oil are used as human and animal food and the oil is used in cosmetics and paints. The chia seed is also rich in protein (16-24% by mass of seed) and fiber (34-56% by mass of seed). Sosa, et al., “Chia crop (Salvia hispanica L.): its history and importance as a source of polyunsaturated fatty acids omega-3 around the world: a review,” J. Crop Res. Fert. 1(104): 1-9 (2016).
Chia was domesticated in Mesoamerica around 2600 B.C. and was a staple food in Mexico between 1500 and 900 B.C. See Baginsky et al. “Growth and yield of chia (Salvia hispanica L.) in the Mediterranean and desert climates of Chile,” Chilean J. Agric. Res. 76(3): 255-264 (2016). Chia is typically grown in tropical and subtropical areas in latitudes ranging from north 20° 55′ north to 25° 05′ south and altitudes from 400 m to 2500 m above mean sea level, such as Australia, Bolivia, Colombia, Guatemala, Mexico, Peru, and Argentina. The plants are sensitive to frost at all development stages and generally cannot be cultivated at higher latitudes and altitudes.
Mexico produces the majority of commercial chia and the Pinta variety is the most commonly cultivated chia variety. Cahill, “Human selection and domestication of chia (Salvia hispanica L.),” J. Ethnobiol. 25:155-174 (2005). Pinta is native to Jalisco, Mexico and approximately 80% of chia grown in Mexico is the Pinta variety. Cahill, “Ethnobotany of Chia Salvia hispanica L. (Lamiaceae),” Econ. Bot. 57: 604-618 (2003). Pinta produces a combination of black and white seeds at a ratio of 9 black to 1 white. See Rovati et al., “Particularidades de la semilla de chia (Salvia hispánica L.),” EEAOC—Avance Agroindustrial. 33: 39-43 (2012). The Chiablanca SC DE RL Company, Jalisco, Mexico, developed a variety known as White Acatic that produces a ratio of white to black seeds of 24:1 (˜96% white seeds).
The Sahi Alba 914 variety was developed in Argentina by TFSB LLC, located in Dover Del., USA. See U.S. Pat. No. 9,686,926, which is incorporated by reference herein. The Heartland variety was developed by the University of Kentucky, Lexington, Ky., USA. See U.S. Pat. No. 8,586,831, which is incorporated by reference herein. There are two presentations of Heartland, one with white seeds and the other with black seeds. Both Sahi Alba 914 and one presentation of Heartland have uniform white seeds. These varieties were developed to bloom in latitudes above 23° north or below 23° south where the photoperiod is greater than 12.5 hours. The Sahi Alba 914 and Heartland varieties are capable of producing chia seed in agricultural zones of the United States and Argentina where the weather is typically colder and hard freezes occur. See, Sosa et al., “Chia crop (Salvia hispanica L.): its history and importance as a source of polyunsaturated fatty acids omega-3 around the world: a review,” J. Crop Res. Fert. 1(104): 1-9 (2016).
Both the seed color and seed mass are important for commercial chia production. The color and mixtures of multiple seed colors (e.g., black, brown, mottled, or white) affects the final color of the product and can lead to color inconsistency among harvests. This is particularly important when the seed oil is used for cosmetics. Uniform seed color is desirable and white seeds are preferable because the oil has a lighter color. In addition, a high seed mass is preferable for a commercial crop because each seed produces more product. The current commercial varieties of chia have variable seed masses ranging from about 840 to about 1325 mg per 1000 seeds. See Table 1, infra. This variability affects the harvest yields of the seed product. Lower seed masses produce a lower yield of seed per hectare.
Previous breeding efforts have predominately focused on developing domesticated chia varieties or those that can be cultivated in temperate regions. Few efforts have been made to generate chia varieties that have uniform seed color and enhanced seed yields. Therefore, there is a need to develop new chia (Salvia hispanica L.) varieties that have uniform seed color, greater seed mass, and high seed yields.